1. Field of the Invention
The present invention concerns a filter, for fuel or other fluids, such as oils or other liquids, or even gases, that is preferably oval or flat-sided in cross-sectional configuration. A design according to this invention permits different functions to be included in an oval, flat-sided, or even round filter design, although an oval design is preferable to a flat design, as it more readily avoids collapse and makes it possible to integrate additional parts for cleanliness, water drainage for the clean side, and so on.
2. Description of Related Art
A brief discussion of certain filter systems for automotive or other applications utilizing multiple full flow and bypass filter arrangements is set forth in commonly assigned, co-pending U.S. patent application Ser. No. 12/467,423, filed May 18, 2009, titled Full Flow Liquid Filter with Integral Bypass Filtration. That discussion is partially reiterated here.
Filter systems for automotive or other applications commonly utilize one of two full flow filter and bypass filter configurations. One such configuration is an arrangement having two separate filtering systems, with a full flow system, which may include more than one filter, depending on flow requirements, and a bypass filter system, which processes only a small percentage of the full fluid volume. In such a configuration, an in-line, series approach is often utilized, with a full flow filter provided downstream of a bypass filter. These systems typically introduce additional costs and components for the automotive assembler and service industry to handle and manage. Vehicle weight is increased as well. U.S. Patent application publication 2008/0078716 to Farmer discloses one such in-line, series approach to filtering.
Evolutions of this configuration include systems having filters with full flow and bypass media stacked upon each other in the same filter housing. Examples of filters having stacked media include apparatuses disclosed by U.S. Patent application publication 2005/0252838 to Fisher and U.S. Pat. Nos. 5,447,627 to Loafman et al., 6,319,402 to Schwandt et al., and 6,350,379 to Roll et al.
Further developments have provided increased filtering capacity in the same or smaller footprint, while also offering high efficiency bypass filtration to “polish” the fluid system and provide integral soot filtration, by fitting bypass filters concentrically within full flow filters. U.S. Pat. Nos. 6,666,968 to Smith et al., 6,787,033 to Beard et al., 7,014,761 to Merritt et al., and 7,090,773 to Meddock et al. provide examples of such developments.